“CoroMil^® MR80 is a double-sided round insert concept with a higher number of inserts as compared to regular round insert cutters”, says Sangram Dash, Global Product Application Specialist for indexable milling tools at Sandvik Coromant. “It is ideally suitable for low depth of cut—up to 3 mm—face milling and profile milling applications in both steel and stainless steel.”

Originally designed for machining cast stainless components in the automotive sector, particularly turbochargers and exhaust manifolds, this product has been further developed to cater to steel milling applications, which require the security of a round cutting edge—such as the die and mould segment. As a result, CoroMill^® MR80 is a most capable and versatile milling concept, offering both higher productivity and economical machining in a wide range of operations, while never compromising on security.

“The round cutting edge is considered to be the most secure edge for challenging materials as well as tough cutting conditions”, explains Dash. “Furthermore, the shim provides additional security for the cutter body, protecting against coining deformation and machining accidents, while also securing the insert in the tip seat by restricting micro-movements during cutting.”

An economical solution, CoroMill^® MR80 features double-sided inserts with 12 indexing possibilities when operated within a 3 mm depth of cut. “That means more parts for each set of inserts”, says Dash. “Also, a higher number of inserts on a cutter body enables a higher table feed and increased productivity. On top of that, the overall security and reliability means less damage to the cutter body and inserts—which in the end helps to cut costs.” Thanks to its lightweight cutting geometry, it is also possible to use CoroMill^® MR80 as a problem-solver in difficult machining situations—even at long overhangs.

“Often automotive cast stainless components, due to their intricate shapes, are mounted on a fixture that may not be suitable for higher cutting loads”, says Dash. “And often in die and mould the cutter must go deep into the mould cavity, mounted on a long adaptor. In both cases the cutting forces must be limited, so that vibration can be avoided. Even if CoroMill^® MR80 is a double-sided negative concept, it works with fairly low cutting forces and is a suitable solution for such applications.”

The CoroMill^® MR80 assortment offers cylindrical and Arbor cutter bodies, with diameters from 32 to 100 mm, 3–12 cutting teeth, even pitch, and shim-protection. All cutter bodies feature internal coolant supply. The double-sided E-L50 inserts offer true and easy indexing (6 + 6), with a 3 mm recommended depth of cut.